Basking Shark sightings in Manx waters

She continued: "Seventeen remained in Manx waters, the Irish sea and the Celtic sea but one swam all the way across the Atlantic. The data we have indicates that we have a local shoal but that sexually mature animals can travel globally."

Full analysis of the data will take a number of months but the pop-off locations indicate that the three sharks spent winter in the same grounds as previously tagged basking sharks.

Despite the importance of the research, Mrs Hall said "funding issues" meant the future of the project was in danger.

"When we started in 2004, no-one knew the behaviours or the understanding for the behaviours and patterns we are seeing. We as a small group of volunteers have answered a lot of those key questions in the last few years.

"We operate on a shoe-string but we simply can't afford the tags unless people sponsor them."